Quite often when I am annotating / highlighting text, the the highlighting tool stops working. The drawing tool still works, but not highlighting. I am using the latest version of prs+, and I think it is that which is causing it.

Has anyone else had this 'bug.' I've posted on the prs+ thread in the dev forum but no one seems to know anyone about it.

I tried it yesterday with my 650 running Analogus PRS+Zork Edition and found no problem with annotations. Maybe it is a bit tricky to do the correct tap after the text-selection, to start the note-selection dialog to choose between typed-notes and handwritten ones.

In any case, feel free to file a issue-report over at the project-page

No, until recently it was fine. I didn't start to tap differently. Just one day I noticed it stopped working but I didn't pay much attention because I wanted to move on with reading. It could be that problem started since last PRS+ update.

I will file a bug if this problem gets solved by installing older PRS+ or removing it.
At the moment I do not have time to experiment but I will do it as soon as possible.